#include<cstdio>
using namespace std;
bool f[1000001];
int v[1000001],x[1000001];
int main()
{
    freopen("pairs.in","r",stdin);
    freopen("pairs.out","w",stdout);
    int n,i,y,maxim=0,j;
    scanf("%d",&n);
    for(i=1;i<=n;++i)
    {
        scanf("%d",&y);
        f[y]=1;
        if(maxim<y)
            maxim=y;
    }
    for(i=1;i<=maxim;++i)
    {
        v[i]=1;
    }
    for(i=2;i<=maxim;++i)
    {
        if(x[i]==0)
        {
            for(int j=i;j<=maxim;j+=i)
            {
                x[j]++;
                v[j]*=i;
            }
        }
    }
    long long sol=0;
    for(i=2;i<=maxim;++i)
    {
        if(v[i]==i)
        {
            int nr=0;
            for(int j=i;j<=maxim;j+=i)
            {
                nr+=f[j];
            }
            if(x[i]%2)
                sol+=((1LL*nr*(nr-1))/2);
            else
                sol-=((1LL*nr*(nr-1))/2);
        }
    }
    printf("%lld\n",((1LL*n*(n-1))/2)-sol);
    return 0;
}